zmcontrol -v
Release 7.2.0_GA_2669.RHEL6_64_20120410002025 CentOS6_64 FOSS edition

I have a weird issue on my zimbra server. I have a setup with multiple backend servers and a seperate proxy and LDAP master. For 2 years everything has been working fine, but lately I've noticed some users having issues with spell check in zimbra web. I am having a hard time pinning down the problem. The users affected seem to be a random collection from different servers and different domains. So for example can spell check, but can not spell check even though they are on the same backend server and in the same domain/COS

If anyone has any ideas where i need to look to troubleshoot this issue, that would be great.

Let me know if you need anymore information from my side.